1. University of Bristol; School of Social and Community Medicine; Canynge Hall 39 Whatley Road Bristol UK BS8 2PS
2. Institute of Education, University of London; Social Science Research Unit; 18 Woburn Square London London UK WC1H 0NR
3. Cardiff University; Cardiff School of Social Sciences; 1-3 Museum Place Cardiff South Glamorgan UK CF10 3BD
4. The University of Melbourne; Jack Brockhoff Child Health and Wellbeing Program, Melbourne School of Population and Global Health; Level 5/207 Bouverie St Parkville VIC Australia 3052
5. University of Florida; Health Outcomes and Policy and Institute for Child Health Policy; PO Box 100177 Gainesville Florida USA 32610-0177